By Brad S. Fresenburg
If you hate raking and bagging leaves, University of Missouri Extension horticulturist Brad Fresenburg has good news for you.
Put your rake and bag away. Get out your mower and go to town.
Fresenburg says mowing leaves is good for the environment. It also takes less time, returns nutrients to the soil and reduces costs.
Many cities and towns ban the burning of leaves. In 1992, the Missouri Department of Natural Resources banned the dumping of yard waste in landfills. Commercial sites and composts popped up in response to the ban.
A regular fall mowing schedule is the first step to reduce the volume of yard waste. If your mower has a bagging unit, you can collect chopped leaves and use them to mulch around trees and shrubs.
Studies from Michigan State University Extension in the 1990s evaluated the effects of leaf mulching on turf under various conditions. Researchers found that soil pH did not change, but organic matter increased. The percentages of carbon and nitrogen stayed constant, which is positive, Fresenburg says.
Another Michigan State study considered how much leaf litter a lawn could handle without significantly damaging the lawn. This study was especially helpful for areas such as municipal parks, low-maintenance ball fields and golf course roughs. Application of leaf mulch, regardless of amount, softened the ground surface, which Fresenburg says was a significant finding for areas used for athletic purposes. Adding leaf mulch in the fall helped fields green quicker in the spring. The more mulch, the quicker the field greened.
Purdue University researchers found no change in turf quality when leaf mulch and nitrogen were applied.
Fresenburg says these and other studies show advantages to using leaf and grass mulch. Missouri’s trees drop leaves over several months, making it a smart option to mow leaves.
“So if you haven’t tried this before, go for it. You may never go back to leaf removal or raking,” he says.
Fresenburg gives the following tips for mowing leaves:
- Use a sharp mower blade.
- Maintain normal mowing heights. Mow at a height of 3-4 inches.
- Mow before leaves pile up too high. More than 3-4 inches of leaves is probably too much.
- Do not let a dense layer of leaves lie on turf more than four days. Rake after an extended rainy spell.
- Do not mow too fast. Leaves do not chop as well. Mow at a normal speed or slightly slower.
- Dry leaves chop better than wet ones. However, dry leaves make dust, so wear a dust mask over your nose and mouth. Always wear safety goggles. Do not mow wet leaves.
- Mulching mowers work best for chopping leaves. If you have a rotary mower, remove sticks, limbs and other objects from the yard before mowing.